The Food and Drug Administration issued a warning letter to the personal genetic test maker 23andMe, demanding the Google-backed company discontinue marketing its signature service until it receives marketing clearance from the agency.

The product under attack, known as the Personal Genome Service (PGS), is designed to test for more than 250 diseases and health conditions, which is why 23andMe has resisted regulation, arguing it is an information rather than a medical service, The Associated Press reported.

The FDA says it isn't buying it, pointing to words taken from the company's own website as evidence otherwise.

"Some of the uses for which PGS is intended are particularly concerning, such as assessments for BRCA-related genetic risk and drug responses ... because of the potential health consequences that could result from false positive or false negative assessments for high-risk indications such as these," officials write. Such fallout could include unnecessary chemotherapy and surgery as well as a false-negative hiding a real risk, they argue.

Changes in self-medication based on results are also listed by the FDA as possible problems associated with the product, noting that while the company filed a submission for clearance for some of these usages, it has "failed to address the issues described during previous interactions" with the agency.

This is not, the FDA says, for lack of opportunity.

"As part of our interactions with you, including more than 14 face-to-face and teleconference meetings, hundreds of email exchanges, and dozens of written communications, we provided you with specific feedback on study protocols and clinical and analytical validation requirements, discussed potential classifications and regulatory pathways (including reasonable submission timelines), provided statistical advice, and discussed potential risk mitigation strategies," it states.

Despite these many exchanges, the FDA said they "still do not have the assurance that the firm has analytically or clinically validated the PGS for its intended uses," which the agency says differ than those expressed in the company's submission.

Company spokeswoman Kendra Cassillo responded, according to the AP, stating: "Our relationship with the FDA is extremely important to us and we are committed to fully engaging with them to address their concerns."